Fitting for thermometers



May 25,1926. 1,586,351 B. H. BRISTOL ET AL FITTING FOR THERMOMETERS Filed March 15. 1924 Patented May 25, 1925.

UNITED STATES 1,585,351 PATENT orFicE.

BENJAMIN H. BRISTOL, ARTHUR G. BEAL, AND MALCOLM B. HALL, OF FOXBORO,

MASSACHUSETTS, ASSIGNORS TO THE FOXBORG COMPANY, OF FOXBORO, MASSA- CHUSETTS, A CORPORATION OF MASSACHUSETTS.

FITTING FOR THERMOMETERS.

Application filed March 15, 1924.

This invention relates to thermometers and has particularly to do with a means for mounting or supporting the bulb or reservoir for the expansible fluid. It finds a particular application in the case of wet bulb thermometers and for that reason we have herein shown as an illustrative example of our invention a construction applied to a socalled psychrometer or wet and dry bulb thermometer such as is used for measuring the humidity of the atmosphere.

Our invention will be well understood by the following description of the particular form chosen for purposes of illustration and shown in the accompanying drawings, wherein I Fig. 1 is a partly diagrammatic View in elevation of a psychrometer installation;

Fig. 2 is an enlarged elevation partly 1n section and partly broken away of the bulbs and their support; and

Fig. 3 is a section on the line 33' of fig. 2, but on a small-er scale.

As an example of our invention we have herein shown (see Figs. 1 and 2) a recording psychrometer or hygrometer having a wet bulb 5 and a dry bulb 7 connected to suitable pressure responsive devices of a recording instrument 9 of the recording pressure gage type by means (see Fig. 2) of capillary pipes 11 and 13 respectively, which pipes are enclosed in and protected by the flexible armor tubing 15. The bulbs proper 5 and 7 may be supported by short sections of rigid tubing 17 and 19 from elements 21 and 23 providing engaging means for sultable supports or clamps for holding the bulbs in position and these elements we shall herein refer to as portions of the bulb casings sinceeach forms a part of the support or frame-work for its respective bulb by which it is handled, positioned and immediately supported.

Our invention more particularly relates to the means for supporting the bulbs and their casings in the place the humidity conditions of which it is desired to measure. The bulbs are preferably supported, as .indicated in Fig. 1 by the diagrammatic showing of an electric fan 2%, in such a manner that any current of air will pass first over the dry bulb '7 so that any moisture evapoiatedfrom the wet bulb will not affect the dry 'h -lhrefi ing- Inthe example shown the Serial No. 699,601.

bulbs are in the vertical position but this is not essential.

In accordance with our invention we provide a suitable support which may consist (see Fig. 2) of a bracket 25 having feet 2'? by means of which it may be secured to a suitable supporting surface to hold the bulb suspended from but suitably spaced away from such surface. T 0 support the wet bulb the bracket may be provided with an en largement 29 having a cylindrical opening 31 of such size as to pass the bulb 5 so that the latter may be inserted from one end of the opening and pass through to the other side of the bracket as will be clearly understood from Fig. 2. At one end of the opening there is provided a seat 33, conveniently tapered, on which is adapted to seat an enlargement or shoulder 35 on the bulb casing 21 and a nut or gland 37 may be provided cooperating with the enlargement on the bulb casing and serving to press this sh0ulder against the seat, thus rigidly supporting the bulb 5 in position. The wet bulb is provided for a purpose later to be explained with a suitable casing 39 of porous earthenware or similar material enclosing the sides and bottom of the bulb and to secure this casing in position the opening 31 1s provided with a seat 41 at the end opposite from the seat 33 against which may seat the end of the casing 39 which may be provided with an enlargement 43 cooperating with a. clamp ing nut or gland 45 conveniently provided with wings or handles 47 to facilitate its operation. Such handles are particularly desirable on the gland for clamping the earthenware casing 39 as they will avoid the use of a wrench which might lead to breakage of the relatively fragile casing.

It will be clear that if the bulb is in position the casing 39 may be applied endwise over the same and secured in position by the gland 45 and likewise this casing may be removed for'replacement, repair or cleaning without disturbing the bulb 5. Also by unscrewing the gland 37 the bulb may be withdrawn endwise, upwardly in Fig. 2, and removed from the support 25 without removing or disturbing the casing 39.

In the operation of the wet bulb thermometer shown the porous casing 39 surrounding the wet bulb 5 is kept filled with water. This water seeps through the interstices of the casing and is evaporated from the outside thereof with a spoon. and cooling eilect dependent upon the humidity of the surrou air. This arrangement has ed advantages over the customary wick. or textile jacket applied around the wet both and dip 'iing into a receptacle ot water. To keep the ca ng supplied with water the ci'ilargemcnt s provided with a water intake port ll) leading to the opening 31 a a point between the seats 8 and ll and phi-(nigh this opening water may be supplied to the interior of the cash 39 in any eon venient manner. in the term of the invention shown the fitting is connected to a supply ot' water under pressure, such as the ordinary cit water supply, entering (see Fig. 1) through pipe To maintain a constunt head of water in the jacket 39 to provide tor uniform operation of the instrument a suitable water containing reservoir 53 is piped up to the opening i?) and a constant level of water is maintained in the res ervoir by means of a valve controlling the main supply through the pipe 51, which valve is governed by a float controlled by the level of water in the re ervoir. A cock 5? may be provided, if desired, for shutting oil the reservoir 43 from the space above the bulb.

l V hen a dry bulb used in connection with the wet bulb it may be supported adj acent the wet bulb on the same bracket and for this purpose an open-sided seat or groove 59 may be provided in the bracket paralleling the bore 31 ot cnlargen'ient 529. The dry bulb may be placed in position by a lateral movement of approach distinguished from an endwise movement of threading the bulb through an opening and the fitting 23 brought to rest in the seat which will support the bulb 7 adjacent the bulb 5 in its casing 39 as shown in Figs. 1 and Suitable clamping means serve to hold the bulb easing la in the seat- 59 and we have herein saown a strap 61 having one end resting on the enlargement 25 and adapted to extend over the fitting A thumb screw (53 extends through the strap (31 and taps into the base of the bracket and, serves to clamp the bulb casing '23 in the seat and to the bracket. [\s best seen from Figs. 1. and 3, the ends of strap ill may be forked so that it may tit a lug (55 on the enlargen'ient 25 and be prevented from turning when screw 63 is set up.

We have described in detail the particular physical construction adapted tor use with a psychrometer illustrated in the accompanying drawings, but this detailed description has had the purpose or making that particular construction clear and is not to be understood as a limitation of the scope of the invention. The inventive idea estem plified by the particular device disclosed might be embodied in various constructions and forms and what. we claim as new and desire to secure by Letters Patent we shall express in the following claims.

Claims.

1. In a wet bulb thermometer a thermometer having a bulb, a supporting base having an opening to pass the thermometer bulb, means at one end of the opening to clan'ip a portion oi the thermometer to secure the bulb to the fitting, a porous cup to enclose the bulb and means at the other end of the opening for independently clamping the porous cup about the bulb.

2. la a wet bulb thern'iometer a base having a. cylindrically apertured enlargement, the aperture being of a size to pass the thermometer bulb, there being a seat adjacent one end ot the aperture, a thermometer having a bulb and a shoulder near the bulb to, cooperate with the seat, a fitting to press the shoulder to the seat, a seat at the opposite end ot the aperture, a porous cup having an open end presented to the seat, a fitting to press the cup against the seat and a water inlet opening to the aperture between said seats.

In a wet bulb thermometer a therm0m eter having a bulb, a porous cup to surround the sides and ends of the bulb and a supporting base having separate means for securing thereto the thermometer bulb and the cup and permitting on manipulation of one such means the withdrawal of the bulb from within the cup without disturbing the cup and on manipulation of the other the removal of the cup from about the bulb without disturbing the bulb.

i. In a wet bulb thermometer a thermometer having a bulb, a porous cup to surround the sides and ends of the bulb, and a supporting base having separate means for securing thereto the thermometer bulb and the cup permittin on manipulation of one of such means the 'ithdrawal of the bulb from within the cup without disturbing the cup or on manipulation of the other the removal of the cup from about the bulb without disturbing the bulb, said base having a water inlet therein independent of said securing means and providing conununication to'the open top of said cup.

5. A psychrometer comprising a dry bulb casing, a wet bulb casing, a ceramic cover to receive the wet bulb and a fitting comprising a base having an apertured enlargement provided with seats adjacent the ends thereof, means to secure respectively to said seats the wet bulb casing and the ceramic cover for the wet bulb and a clamp adapted to engage laterally with the dry bulb casing to clamp it against the base adjacent the enlargement.

6. A. psychrometer comprising a dry bulb casing, a wet bulb casing, a ceramic cover to receive the Wet bulb and a fitting comprising a base having an apertured enlargement, provided with seats adjacent the ends there of, means to secure respectively to said seats the Wet bulb casing and the ceramic cover for the Wet bulb, there being a seat in said base paralleling said enlargement and adapted to receive the dry bulb casing by a lateral movement of the latter, a clamp overlying the seat and means to press it toward the base.

7 A psychrometer comprising a dry bulb casing, a \vet bulb casing, a ceramic cover to receive the Wet bulb and a fitting comprising a base having an apertured enlargement, provided With seats adjacent the ends thereof, means to secure respectively to said seats the Wet bulb casing and the ceramic cover for the Wet bulb, there being a seat in said base paralleling said enlargement and adapted to receive the dry bulb casing by a lateral movement of the latter, a strap having an end supported on the enlargement and extending over said seat and a clamping screw connecting said strap and the base.

8. A thermometer having a bulb, a bulb casing having a shoulder, a fitting comprising a sleeve having an opening through which the bulb may be passed,'a nut on said casing threaded to said fitting at one end of the opening and cooperating With said shoulder to clamp the casing in fixed position in said fitting, a seat at the other end of the opening, a porous ceramic cup seating on said sleeve and surrounding the sides and ends of the bulb and a threaded fitting to clamp the cup against the seat.

9. A thermometer fitting comprising a sleeve having an openingthrough which the bulb may be passed, a seat adjacent one end of the sleeve to receive a portion of the bulb casing, a nut on said sleeve to cooperate With said portion of the casing, a seat at the other end of said sleeve, a cover to enclose the bulb fitting the seat and a second nut on said sleeve to clamp the cover to its seat.

In testimony whereof, We have signed our names to this specification.

BENJAMIN H. BRISTOL. ARTHUR e. BEAL. MALCOLM B. HALL. 

